Quick Reference Material: Dictionaries, verb books and other reference material. If you are serious about learning Spanish you MUST have a good verb conjugation book and a good dictionary. Click on the pictures to get more details about each one of them and to purchase them directly from Amazon.
A Little Light Spanish Reading: "Editorial Santillana" and "La Universidad de Salamanca" offer a series of books specifically developed for students. The degree of difficulty and new vocabulary is color coded. On the list below, row 1 is level 1, row 2 is level 2, etc. They are amazing little books to familiarize yourself with Spanish structures, gain vocabulary and... to learn while having fun...! Many books include an audio CD. I strongly recommend them.
For those who enjoy Grammar...: The "Practice Makes Perfect" series is one of the best I have seen. They follow the same pattern or style of showing different concepts. If you try one and you like it, you may want to try other books of the series.
A little bit of everything: Several items with Spanish in mind, of course. DVDs, translators, full courses, etc.